In addition, the photosynthesis, growth and yield formation of crops are all related to temperature. The temperature requirement of crop growth can be expressed by three base points temperature. Three base point temperature refers to the lowest, best and highest temperature of crop growth. When the temperature is lower than the minimum temperature or higher than the maximum temperature, the crops stop growing. When the temperature is in the optimum temperature range for crop growth, the crop grows fastest and has the highest yield. When the temperature is between the lowest temperature and the optimum temperature for crop growth, with the increase of temperature, the growth speed and yield of crops increase. When the temperature is between the optimum temperature and the highest temperature for crop growth, with the increase of temperature, the growth rate and yield of crops will decrease. Different crops and the same crop have different three-base point temperatures at different growth stages. Although the temperature is lower than the optimum temperature, proper temperature increase is beneficial to crop growth and yield increase. However, when the temperature is close to the optimum temperature, the increase of temperature will be unfavorable to crop growth and even lead to crop yield reduction.
The main means of crop production to cope with climate warming include the following two aspects: first, according to the changing characteristics and trends of heat resources in various places, revise or readjust crop layout and zoning, and adjust planting system or crop varieties; Second, according to the characteristics of local temperature changes, select crop varieties with large temperature adaptation range. Choosing suitable late-maturing varieties can adapt to the long enough crop growth period and obtain high yield in the case of global warming.
(Yang Xiaoguang, Chu Qingquan)